(This answer assumes you are in the US)
It is unlikely that you would get satisfactory digital signals using the same antennas you tried before.
As far as TV antennas are concerned, digital and analog TV signals are identical. But an analog tuner can frequently display a poor image under conditions where a digital tuner cannot maintain a signal lock.
Asking neighbors what there experience has been is a good place to start.
If you want to pursue this, its better to spend some time/money finding the best antenna for the job. The first link below has a place that can tell you what directions & frequencies of your local TV transmitters. The second link has reviews of various TV antennas.
If you don't have a resent vintage digital (ATSC) tuner, the government is starting a coupon program in Jan 2008 that will let you buy a digital tuner/converter for about $20. It only outputs SD quality signals, but it would be a cheap way to see what kind of results you can get. Check in Jan to see which of the cheap boxes does the best in weak signal environments.
If you don't end up using the $20 box, you can probably find someone who can use it. (It looks like I will need a third one, and the government will only give out two coupons per household 8- )